Method of manufacturing a semiconductor device
A method of fabricating a semiconductor device is disclosed. An example method sequentially forms a gate insulation film and a sacrificial film on a semiconductor substrate. In addition, the example method forms a bowing hollow by selectively etching the sacrificial layer, forms gate material on the gate insulation film exposed through the bowing hollow and the sacrificial film, and forms a gate by anisotropically etching the gate material such that the gate material remains on an inner side wall of the bowing hollow.
1. A method of fabricating a semiconductor device, the method comprising:
sequentially forming a gate insulation film and a sacrificial film on a semiconductor substrate;
forming a bowing hollow by selectively etching the sacrificial layer;
forming gate material on the gate insulation film exposed through the bowing hollow and the sacrificial film; and
forming a gate by anisotropically etching the gate material such that the gate material remains on an inner side wall of the bowing hollow.
2. The method of claim 1 , wherein in the anisotropic etching, an etching in a vertical direction is faster than that in a horizontal direction.
3. The method of claim 1 , wherein the anisotropic etching is one of an etch back method and a chemical mechanical polishing method.
4. The method of claim 1 , wherein, in forming the gate, the gate material is anisotropically etched to have a width corresponding to a width of an objective gate.
5. The method of claim 1 , wherein, in the anisotropic etching, the gate material is over-etched until the gate material has a width corresponding to a width of an objective gate.
6. The method of claim 5 , wherein the gate material is polycrystalline silicon.
7. The method of claim 1 , wherein, in the anisotropic etching, the gate insulation film on the bottom of the bowing hollow and top surfaces of the sacrificial film are exposed.
8. The method of claim 1 , wherein the step of forming the bowing hollow includes forming the bowing hollow by selectively etching the sacrificial film such that the blowing hollow has a width corresponding to a width of an objective gate plus a width of an adjacent gate plus a distance between the objective gate and the adjacent gate.
9. The method of claim 1 , wherein the sacrificial film is selectively etched using one of and end point detection apparatus and a method of etching for a fixed time.
10. The method of claim 9 , wherein the sacrificial film is a nitride film.
11. The method of claim 1 , wherein, in forming the bowing hollow, an extent of bowing is proportional to a width of an objective gate.
12. The method of claim 1 , wherein, in forming the gate, two gates are simultaneously formed by leaving the gate material on both inner side walls of the bowing hollow.
13. The method of claim 1 , wherein the sacrificial film is a nitride film.
14. The method of claim 1 , wherein the gate material is polycrystalline silicon.
15. The method of claim 1 , wherein a thickness of the sacrificial film is proportional to a width of an objective gate.
16. The method of claim 1 , wherein a surface of the gate is a curved surface.
17. The method of claim 1 , further comprising, after the step of forming the gate, a step of removing the sacrificial film.
18. The method of claim 17 , wherein the sacrificial film is removed by a wet etching.
19. The method of claim 18 , wherein the sacrificial film is a nitride film.
20. The method of claim 1 , wherein the gate insulation film is an oxide film.